PDA

View Full Version : Acceptable intonation variation



Flibble
01-17-2017, 10:35 PM
Apologies if this is a silly question or retreads old ground.

I've been looking at discussions about intonation, but am confused about acceptable variation. Is everyone aiming for perfection all the way down the fret board? Or is there a level where you think 'that'll do!'? I've read the threads on here and checked youtube videos but there isn't much discussion of this particular question.

Checking my own, there seems to be upto about 10 cents variation up the board. On most tuner apps this is within the 'green'. Particularly this seems relevant as it's so hard to get a clear reading on many tuners.

I'd appreciate peoples' thoughts.

JackLuis
01-17-2017, 11:25 PM
I've wondered the same thing and generally I get an answer that it should be perfect. From my tests over the last two years and research, intonation is effected by Saddle height and scale compensation, nut height and string diameter and linear mass. All these factors have to balance fairly precisely. This assumes the fret board spacing is the correct ratio.

Tuner precision has to be considered as well but the accuracy of the of a digital tuner is dependent on it's time standard, and frequency resonators in the 100 Khz range should be pretty easy to make and provide a good time base for the ~2,500 Hz highest frequency necessary for a Uke.

It is surprising how good some peoples "ears" are though.

Booli
01-18-2017, 12:49 AM
First thing to understand that 'perfect' intonation is not really possible when all frets are parallel to each other, as well as nut and saddle.

Current fret spacing calculations are a 'compromise' or averaging of frequencies, and the ideal scenario that creates the foundation for the 'possibility' of perfect intonation is a 'fanned fret' spacing in which the treble side of the fretboard is more like we know it now, but the bass side is angled with frets further apart, and moreso as you go from nut to saddle, in much the way a folding Japanese Geisha holds her fan when open...

Doing the fanned frets removes the need for compromise in spacing.

Having said the above, it is surprisingly that most average folks have a wide bandwidth of how tolerant their hearing is of poor intonation. It takes some musical training unless you are born with perfect pitch, as well as having an instrument that has been setup at both nut and saddle, as well as the truss rod, if it has a truss rod, in order to get very good intonation.

If you ear is not trained or your instrument was poorly made, you will not 'hear' he poor intonation, but a tuner will.

If this is the dilemma, I'd first ask, has the instrument had a 'setup'?

I did not have the hearing perception for intonation being off unless it was off by 20 cents or more, until I got a concert Flea. I played it exclusively for about 3 months and then picked up my other ukes that had no setup and it was simply AWFUL.

My ear had adjusted to the better intonation of the Flea, and I set about learning to, and perfecting the setup of those other ukes, by adjusting the nut and saddle until the intonation was as good as the concert Flea. Which was no more than +2 cents at the 2nd fret and 100% dead-on at frets 7 and 12.

So, how bad is too bad? Depends upon your own ear.

Also, Intonation varies with string tension, which is a factor of string density manifest as the string diameter to everyone who is not a scientist, but depending upon scale length, intonation can very quite a bit, especially dependant upon string materials, nylon, Nylgut, Fluorocarbon, wound strings, etc..

so there is no perfect answer that fits everyone, but for my ear, if the instrument is perfectly in tune on all open strings, and is more than about 4 cents sharp or flat, I can hear it and it annoys me enough that I cannot play that instrument, it's like fingernails on a chalkboard to me, and and cannot be turned off

So all of my instruments are either setup by me, setup by the shop or vendor, or came setup by the maker to a very good level of intonation accuracy.

Once you get used to better intonation, there is no going back, you cannot mask poor intonation once your ear is attuned better.

You can 'decide' not to care, but if you are still playing an instrument with poor intonation, there is always going to be this horror of sour tone that you cannot un-hear ever again.

Proceed with caution, as there is no refund possible once you acquire this ability, which is both a blessing and a curse.:)

Booli
01-18-2017, 01:03 AM
I've wondered the same thing and generally I get an answer that it should be perfect. From my tests over the last two years and research, intonation is effected by Saddle height and scale compensation, nut height and string diameter and linear mass. All these factors have to balance fairly precisely. This assumes the fret board spacing is the correct ratio.

Tuner precision has to be considered as well but the accuracy of the of a digital tuner is dependent on it's time standard, and frequency resonators in the 100 Khz range should be pretty easy to make and provide a good time base for the ~2,500 Hz highest frequency necessary for a Uke.

It is surprising how good some peoples "ears" are though.

I agree with most of what you've said here, but in most of my recordings of ukulele, the spectrum analyzer shows
reasonable levels (-25db up to 0db) in frequencies from about 90 Hz up to about 7kHz or 7,000 Hz, but I'm not sure how that applies to whatever math might be used in the programming of an electronic tuner -- please tell or share a link if you know how this works

Thanks brother :)

Rakelele
01-18-2017, 06:07 AM
Having tested several ukes, including some very expensive ones, all properly setup, I would say that +/- 10 cents is acceptable (or realistic). Some of the variation has to do with the player, pressing harder or softer and therby bending the string more or less.

Flibble
01-18-2017, 06:23 AM
Thanks all

Yes it's a tricky one isn't it. I think for me it's an illustration of getting overly focused on a new hobby! It does seem like there are so many variables that staying in one place with intonation is impossible. My Uke currently has horribly squeaky bio-nylons on, so I am sure that measurements will change when I finally change them.

I'm sure I will keep striving though!

JackLuis
01-18-2017, 07:02 AM
I just got a new Tenor and am playing string roulette with it to get the sound "right." the Super Nylgut High G set that came with it is too high for my voice to sing to and while the Aquila's intoned perfectly (1-12) I can't sing that high and sound reasonable to myself.

I'm off to get some D'Addario Carbons for it.

What Booli said about developing your 'ear' is very true. I'm not as critical as he is, but I've only been playing 2 years.

Rakelele
01-18-2017, 07:24 AM
As for changing strings: keep in mind that different brands of strings will intonate differently (because of different gauges etc.). Theoretically, each set of string will require a slightly different setup (mainly compensation at the saddle/nut). Again, intonation on a fretted instrument is a compromise. More important than what a tuner tells you might be that the instrument is in tune with itself: is the fourth string at the fifth fret the same pitch as the third string open fret etc.

plastuku
01-18-2017, 04:16 PM
More important than what a tuner tells you might be that the instrument is in tune with itself: is the fourth string at the fifth fret the same pitch as the third string open fret etc.

This is something that really jumped out at me recently. I decided to try Cuatro tuning (low reentrant) and did it first on my tenor Outdoor, which has excellent intonation. All sounded good, so I did the same thing to my tenor Caramel and got some HORRIBLE sounds.

Cuatro tuning causes some two-string unisons with one string fretted and the other open. These play as octaves in a linear tuning and sound okay to me. I think what's happening has to do with the ratio of frequency mismatch. The Caramel goes a little sharp on any fretted note, where the OU doesn't.

So, let's say I'm playing an octave in linear tuning: 4th string at the second fret is A3 at 220Hz, and the open first string is A4 at 440 Hz. If my Caramel's intonation sharpens everything by 10 Hz (just to pick a number), then the perceived difference in pitches is 230/440 or about two percent. But if I use the Cuatro tuning, that becomes an imperfect unison at 230/220 or about five percent; much more noticeable.

Does this make sense?

(BTW, I decided I don't like the Cuatro after all.)

Booli
01-18-2017, 04:31 PM
I tune my ukes primarily to the fifth fret. This creates a better compromise over the entire neck. I don't see the wisdom of tuning to the instrument's most extreme and atypical point.

for me...

If intonation is ok at the 12th fret, then the saddle is properly compensated.

and also

If the intonation is ok at the 1st and 2nd frets then the fret slots are low enough that 1st-position chords will be in tune and not sharp from fret slots that are too high.

Just my humble experience - no 'rules' intended here.